'Top Posting' versus 'Bottom Posting' versus 'Interleaved Posting'

When a message is replied to in Usenet... or,for that matter, e-mail or Internet forums, the original message can often be included for referenced (or "quoted") in a variety of different posting styles.

The main options are top-posting — replying above the original message; bottom-posting — replying below; or interleaved posting (which is arguably the preferred method). While each online community differs on which styles are appropriate or acceptable, within any community the use of the "wrong" method risks being seen as a major breach of netiquette, and can provoke vehement response from community regulars.

Top Posting

Please note that top-posting in Usenet is unacceptable and considered bad netiquette

Most seasoned Usenet users believe that "top-posting" is appropriate for interpersonal e-mail only and completely inappropriate in the usenet environment. Inline posting (or "trimmed" bottom posting) should always be applied to threaded discussions such as newsgroups. Objections to top-posting on newsgroups, as a rule, seem to come from pool of intelligent people who first went online in the earlier days of Usenet, and in communities that date to Usenet's early days. Newer online participants, especially those with limited experience of Usenet (and indeed computing in general), tend to be less sensitive to arguments about posting style.

The default quote format and cursor placement of many popular e-mail applications, such as Microsoft Outlook, Gmail and Usenet.com.au, seemingly encourages top-posting. Microsoft has had a significant influence on top-posting by the ubiquity of its software; its e-mail and newsreader software places the cursor at the top by default, and in several cases makes it difficult not to top-post (this is caused by a bug present on most flavours of Microsoft Outlook where the quotation symbols are lost when replying in plain text to a message that was originally sent in HTML/RTF, along with the fact that on the default Microsoft Outlook setup, no quotation symbols are generated at all — this makes it very hard to distinguish between new and quoted text)... many users have accepted this as a de facto standard. Some people argue that the cursor appears at the top of the post simply because the news client doesn't know how you will reply, and it relies on the user to either reply in an interleaved style, or by simply positioning the cursor at an appropriate point within the text. Certainly, a good Usenet post will also 'trim' irrelevant parts of a post and nonsense characters or text that may appear.

Top-posting makes posts completely incomprehensible. First: In normal conversations, one does not answer to something that has not yet been said. So it is unclear to reply to the top, whilst the original message is at the bottom. Second: In western society a book is normally read from top to bottom. Top-posting forces one to stray from this convention: Reading some at the top, skipping to the bottom to read the question, and going back to the top to continue. This annoyance increases even more than linear with the number of top-posts in the message. If someone replies to a thread and you forgot what the thread was all about, or that thread was incomplete for some reasons, it will be quite tiresome to rapidly understand what the thread was all about, due to bad posting and irrelevant text which has not been removed.

Bottom Posting

Another style of replying to messages has been dubbed "bottom-posting". The reply is placed below the quote to preserve the logical order of the replies and follow the Western reading direction from top to bottom.

Bottom posting is the most acceptable form of replying to Usenet. If, for no other reason than consistency, posters should maintain to a common standard. A mixed post that makes reference to other messages that are a combination of bottom-posting and top-posting are hard to read and they soon lose the readers interest.

Scrolling down through a post to find a reply is inconvenient, especially for short replies to long messages, and many inexperienced computer users may not know that they need to scroll down to find a reply to their query. When sending an untrimmed bottom posted message, one might indicate inline replies with a notice at the top such as "I have replied below." However, as many modern mail programs are capable of displaying different levels of quotation with different colors (as seen here), this is not so much of an issue any more.

Inline replying

In practice, "bottom-posting" is usually extended to "inline replying" (or "interleaved reply" or "point-by-point rebuttal", though it is sometimes also called "bottom-posting"), where chunks of quoted material and subsequent replies are interleaved, giving a specific response to each paragraph or sentence. This creates a natural, chronological ordering to each segment of the discussion stored within a message. It is not required for the poster to paraphrase each issue being addressed, as comments can be made point-for-point against the exact quote of the original message, making for a more structured, disciplined and unambiguous reply.

This style of posting is frequent on Usenet, Internet forums, and other situations in which the previous discussion is publicly available. This is also sometimes used in email.

Inline replies keep related sections of a discussion together within a message. As such it is easier to fork off parallel 'threads' of discussion from a single source message, each perhaps dealing with only one specific point (or subset of points) from the original.

If quoting large sections of discussion, particularly in newsgroup discussions, it is recommended to trim the message such that only a taste of the original (a reminder) is left — even if this means leaving a sentence hanging. The chunks of quoted text are typically "trimmed" (leaving only the relevant quoted material), and some refer to this style as "trim-posting". Paragraphs which are not replied to are frequently "snipped" completely. In such a circumstance it is customary to append an indicator, usually in the form of a square bracketed tag to the effect of [snipped], [trimmed], or simply [...]. This also prevents signature blocks, free email service ads, and corporate disclaimers from piling up in a growing useless "tail" at the end.

If the precise nature of the quote is not immediately apparent from the remaining text, it is polite to include a brief 'subject' text in the bracket, so the original author's words are not misunderstood by readers unfamiliar with the original.

Double-quoting

Another style involves replying in an interleaved manner to selected quotes from the original message, as described above, but then following this with a fullquote of the entire message, as if top-posting. This results in some portions of the original message being quoted twice, which is considered wasteful.

Netiquette Guidelines

In the words of RFC 1855, the RFC Netiquette Guidelines, which comprise a comprehensive set of voluntary netiquette conventions:

This section of the RFC is discussing public archived postings such as mailing lists and newsgroups. For interpersonal e-mail, the subject line is often sufficient to remind the sender of what was being discussed, and no quoting of any type is necessary to indicate a reply. However, if one is politely addressing points of a conversation, the points discussed should be explicitly stated or quoted inline. This is stated in the RFC regarding interpersonal communication such as email:

Some would add that one should also include a blank line in between quoted material and responses to ensure that they are clearly set off from one another. Some mail programs may even try to re-word-wrap entire paragraphs and cause quotes and replies to be jumbled together illegibly if they are not cleanly separated. A common mistake is to leave "tails" of greater-than signs (">") above or below a quoted block, running into the preceding or following paragraph of new material, instead of creating an entirely blank line as a separator.

Attribution lines

Since quoted material frequently becomes several levels deep, if a relevant point is retained during a discussion, "attribution lines" are commonly used to indicate the author of each part of the quoted material.

Many mail user agents will add these attribution lines automatically to the top of the quoted material. Retaining these lines as the discussion continues results in this style:

Overquoting (and top-posting implications)

It's very important to not overquote. Keep the quoted text short, meaning remove everything you aren't addressing directly in your reply, as it's only a waste of space and bandwidth. That's something most top-posters aren't doing, another reason why those top-posting people aren't famous or well regarded on Usenet. It's also common practice to sometimes break quotes into smaller pieces and comment every piece separately. This technique is neither possible when top-posting and thus we have another argument that speak against this silly and unworkable style of posting.

Quote characters

Nowadays some people thing it's funny to use other chars for quoting, like "|", ":", "*", "$" and so on. Sometimes people will lead their text with their name. Such use of lead in characters is frowned upon. The correct way is using ">". The > character is easy to read, doesn't cause any trouble and has been used for quite a long time now.